Visiting, meditating or praying in Istanbul’s Hagia Sophia (Holy Wisdom in Greek) is aesthetically and emotionally exhilarating. Built by the Eastern Roman Emperor Justinian I between 532 and 537 A.D., its circular dome covers what was for a thousand years the largest indoor space in the world. It remains architecturally dazzling.

Justinian became Emperor of the Eastern Roman Empire in August 527, ruling a territory stretching from Greece to Arabia. The Roman Empire was then half the size it had been because 51 years earlier in 476 the Empire in Western Europe finally collapsed after fighting for some three centuries with various German tribes, so-called barbarians.